Research on Suitable Anti-Sliding Piles Spacing Considering of Soil Arch Effect in Colluvial Landslide

2013 ◽  
Vol 671-674 ◽  
pp. 262-265
Author(s):  
Lin Na Sun ◽  
Jing Li ◽  
Lei Wang
Keyword(s):  
Equation Of State ◽  
Internal Friction ◽  
Friction Angle ◽  
Engineering Practice ◽  
Stress Model ◽  
Arch Effect ◽  
Soil Arch ◽  
Adjacent Soil ◽  
The Relationship ◽  
Colluvial Landslide

Suitable anti-sliding spacing is one of the most important parameters in the design of anti-sliding piles. It is closely related to whether the soil arch effect can be completely played. Based on analyzing the stress model of soli arch effect on the adjacent soil, the relationship between the piles spacing and the cohesive force c as well as the internal friction angle of the soil behind piles is proposed. The reasonable pile spacing formula which based on the limiting equilibrium equation of state was deduced and verified the method with engineering practice.

Experimental Study of Rockfill Particle Breakage

2014 ◽  
Vol 900 ◽  
pp. 445-448
Author(s):  
Zhi Hua Xu ◽  
Da Wei Sun
Keyword(s):  
Internal Friction ◽  
Large Scale ◽  
Reference Value ◽  
Friction Angle ◽  
Confining Pressure ◽  
Particle Breakage ◽  
Internal Friction Angle ◽  
Dam Construction ◽  
Confining Pressures ◽  
The Relationship

As the high concrete faced rockfill dams construction, grain breakage gradually become the factors that influence the high dam construction which can not be ignored. This text based on the master of rockfill of shuibuya dam as the experimental material, getting and analyzing the particle breakage data under different confining pressure through the large-scale triaxial test, and the results show that the particle breakage index increases with the increase of confining pressures. The relationship between particle breakage index and confining pressure can be expressed by formula;Particle breakage increase leading to reduced internal friction angle and the shear strength of rockfill, and the author newly introduced two broken variable to describe the relationship which can be expressed by the formula between the particle breakage and internal friction angle, it has certain reference value for establishing constitutive model considering particle breakage.

Numerical Simulation of Triaxial Tests for Coarse-Grained Soil Considering the Initial Fabric of Samples Grain

2010 ◽  
Vol 143-144 ◽  
pp. 873-878
Author(s):  
Guang Jin Wang ◽  
Xiang Yun Kong ◽  
Yi Lei Gu ◽  
Chun He Yang
Keyword(s):  
Numerical Simulation ◽  
Internal Friction ◽  
Random Distribution ◽  
Friction Angle ◽  
Internal Friction Angle ◽  
Coarse Grained ◽  
Triaxial Tests ◽  
Strength Parameters ◽  
The Relationship ◽  
Coarse Grained Soil

The strength parameters of granular coarse-grained soil are the critical factor that affects the stability of ultra-high dump. The soil particles of different size have no sorting and random distribution, which leads to the initial fabric of sample grain uncontrolled in the laboratory test of coarse-grained soil, therefore, only relying on the laboratory testing is difficult to obtain the reliable strength parameters of coarse-grained soil. Based on Cellular Automata method, combining the laboratory triaxial tests of coarse-grained soil developed the HHC-CA model which generated the coarse-grained soil samples of different initial fabric of grain to characterize the heterogeneous and random distribution of coarse-grained soil grain group. Then by means of FLAC3D, conducting triaxial numerical simulation tests of coarse-grained soil and discussing the relationship between the gravel contents of samples shear band and samples and internal friction angle. Moreover, the shear strength model for different coarse-grained contents is established. Numerical simulation results indicated that the relationship between internal friction angle of coarse-grained soil and gravel contents of samples shear band were increasing function in the same size grading. According to the increasing of samples gravel contents, the internal friction angle might reduce, but the mean internal friction angle significantly increased with the increment of samples gravel contents.

scholarly journals Triaxial Shear Test on Hydrochloric Acid-Contaminated Clay Treated by Lime, Crushed Concrete, and Super Absorbent Polymer

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Fang Tong ◽  
Qiang Ma ◽  
Xing Hu
Keyword(s):  
Shear Strength ◽  
Hydrochloric Acid ◽  
Internal Friction ◽  
Acid Concentration ◽  
Friction Angle ◽  
Double Electric Layer ◽  
Internal Friction Angle ◽  
Engineering Practice ◽  
Hydrochloric Acid Concentration ◽  
Crushed Concrete

Acid pollution weakens the bearing capacity of subgrade, and discarded concrete occupies land. The mechanical properties of hydrochloric acid-contaminated clay were investigated by triaxial consolidation undrained tests. Also, the theory of diffusion double electric layer was employed to explain the change principle of cohesion and compression characteristics of hydrochloric acid-contaminated clay. In addtion, the curing effects of lime, crushed concrete, and SAP on the shear strength of hydrochloric acid-contaminated clay were compared. The triaxial test results show that cohesion decreased with the increase of hydrochloric acid concentration. The internal friction angle firstly increased and then decreased, and the change of internal friction angle was less affected by acid concentration. The curing effect of crushed concrete was similar to that of lime, which was better than lime. SAP could only improve the cohesion of the hydrochloric acid-contaminated clay; the internal friction angle decreased significantly; the three kinds of curing materials could significantly improve the cohesion of acid-contaminated clay to be higher than the natural clay, improving the shear strength to a certain extent. Additionally, the theory analysis illustrated that due to the change in the thickness of the diffusion layer between the clay particles, the van der Waals force between the particles changed, and the colloidal formation of the micelles led to changes in cohesion. The study can provide references to the treatment of contaminated soil in engineering practice.

Testing Study on the Change Law about Internal Friction Angle of Geogrid Reinforced Clay under many Times Freezing-Thawing Cycles

2012 ◽  
Vol 594-597 ◽  
pp. 186-193
Author(s):  
Rong Fei Zhao ◽  
Yong Ning Mi ◽  
Wei Gao
Keyword(s):  
Internal Friction ◽  
Initial Moisture Content ◽  
Influence Factors ◽  
Friction Angle ◽  
Regression Equation ◽  
Internal Friction Angle ◽  
Engineering Practice ◽  
Angle Change ◽  
Testing Data ◽  
Reinforced Clay

This paper uses quadric orthogonal rotating combination design test, obtains the internal friction angle change values under given many times freezing-thawing cycles for the geogrid reinforced clay with different degree of compactions, moisture contents and reinforcement spacings. Through analysis of the test data and mathematical calculation to get the regression equation about the internal friction angle change value related with fillers compaction degree, initial moisture content and reinforcement spacing, and test the conspicuousness about the equation and the influence factors. Applies the equation to calculate the internal friction angle change values in the else test conditions, the results show that the calculated values and the testing data fit well, the equation can be used for initial calculation of the under many times freezing-thawing cycles. The regression equation provides a theoretical reference for the engineering practice of geogrid reinforced clay.

Experimental Study of the Relationship between Matric Suction and Strength of Unsaturated Residual Clay in Xiamen under Different Drying-Wetting Cycle Paths

2013 ◽  
Vol 838-841 ◽  
pp. 680-684
Author(s):  
Dong Xia Chen ◽  
Ming Xin Meng ◽  
Ji Wei Luo
Keyword(s):  
Compressive Strength ◽  
Shear Strength ◽  
Internal Friction ◽  
Unconfined Compressive Strength ◽  
Characteristic Curve ◽  
Friction Angle ◽  
Matric Suction ◽  
Internal Friction Angle ◽  
The Relationship ◽  
Cycle Path

To discuss the relationship between matric suction and strength under different drying-wetting cycle paths of residual clay, soil water characteristic curve was determined by the filter paper method. The shear strength, unconfined compressive strength and matric suction were obtained during desorption and adsorption at the drying and wetting cycle. The experimental results show that the matric suction of soil specimens subjected to different drying and wetting cycle paths are different although at the same water content. Contributions of internal friction angle and cohesion to shear strength are different at different matric suction. In the low matric suction stage, matric suction mainly contribute to shear strength by affecting the cohesion, yet in the high matric suction stage by increasing both the internal friction angle and cohesion; in the transition matric suction stage, the contribution of cohesion decreases while the contribution of internal friction angle increases. Furthermore, the unconfined compressive strength of specimens subjected to the drying and wetting cycle path of desorption first and then adsorption is reduced and increase with the opposite path.

Active Limit Equilibrium Method of the Stability Analysis for Soil Slopes

2012 ◽  
Vol 594-597 ◽  
pp. 636-641
Author(s):  
Ying Huang ◽  
Zu Lian Zhang ◽  
Ke Sheng Jin
Keyword(s):  
Internal Friction ◽  
Moisture Content ◽  
Limit Equilibrium ◽  
Earth Pressure ◽  
Friction Angle ◽  
Internal Friction Angle ◽  
Critical Moisture Content ◽  
Soil Slopes ◽  
Critical Moisture ◽  
The Relationship

The stability of the soil slopes can be judged according to the critical moisture content and the actual moisture content when the soil slopes be in the limit equilibrium state. From the perspective of earth pressure, the critical moisture content is the moisture content when the soil slopes be in the active limit equilibrium state, at this time, the active earth pressure is 0. The critical moisture content can be determined and the stability of the slopes can be judged according to the relationship of the soil parameters and the moisture content and the active earth pressure being 0. The critical moisture content of the upright or declining cohesionless slopes can be determined according to the relationship of the internal friction angle and the moisture content. The critical moisture content of the upright cohesive slopes can be determined by solving the equation of the critical moisture content. For the declining cohesive slopes, first, the cohesive soil having the cohesion and internal friction angle is replaced by only having the equivalent internal friction angle of the cohesionless soil according to the principle of the equal strength, then, the critical moisture content can be determined according to the relationship of the equivalent internal friction angle and the moisture content of the declining cohesionless.

Characterization of Shear Strength and Interface Friction of Organic Soil

2020 ◽  
Vol 857 ◽  
pp. 203-211
Author(s):  
Majid Hamed ◽  
Waleed S. Sidik ◽  
Hanifi Canakci ◽  
Fatih Celik ◽  
Romel N. Georgees
Keyword(s):  
Shear Stress ◽  
Shear Strength ◽  
Internal Friction ◽  
Moisture Content ◽  
Water Content ◽  
Friction Angle ◽  
Structural Materials ◽  
Organic Soil ◽  
Internal Friction Angle ◽  
Interface Friction

This study was undertaken to investigate some specific problems that limit a safe design and construction of structures on problematic soils. An experimental study was carried out to examine the influence of loading rate and moisture content on shear strength of organic soil. Influece of moisture content on interface friction between organic soil and structural materials was also attempted. A commonly used soil in Iraq was prepared at varying moisture contents of 39%, 57% and 75%. The experimental results showed that the increase in water content will decrease the shear stress and the internal friction angle. An increase of the shearing rate was found to decrease the shear stress and internal friction angle for all percetanges of water contents. Further, direct shear tests were carried out to detect the interface shear stress behavior between organic soil and structural materials. The results revealed that the increase in water content was shown to have significant negetavie effects on the interface internal friction and angle shear strength.

scholarly journals Strength Assessment of Broken Rock Postgrouting Reinforcement Based on Initial Broken Rock Quality and Grouting Quality

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Hongfa Xu ◽  
Hansheng Geng ◽  
Feng Chen ◽  
Xiao Chen ◽  
Liangliang Qi
Keyword(s):  
Rock Mass ◽  
Internal Friction ◽  
Growth Rates ◽  
Strength Criterion ◽  
Friction Angle ◽  
Uniaxial Tensile ◽  
Strength Assessment ◽  
Uniaxial Tensile Strength ◽  
Quantitative Calculation ◽  
Grouting Reinforcement

To estimate postgrouting rock mass strength growth is important for engineering design. In this paper, using self-developed indoor pressure-grouting devices, 19 groups of test cubic blocks were made of the different water cement ratio grouting into the broken rock of three kinds of particle sizes. The shear strength parameters of each group under different conditions were tested. Then this paper presents a quantitative calculation method for predicting the strength growth of grouted broken rock. Relational equations were developed to investigate the relationship between the growth rates of uniaxial compressive strength (UCS), absolute value of uniaxial tensile strength (AUTS), internal friction angle, and cohesion for post- to pregrouting broken rock based on Mohr-Coulomb strength criterion. From previous test data, the empirical equation between the growth rate of UCS and the ratio of the initial rock mass UCS to the grout concretion UCS has been determined. The equations of the growth rates of the internal friction coefficient and UCS for grouting broken rock with rock mass rating (RMR) and its increment have been established. The calculated results are consistent with the experimental results. These observations are important for engineered design of grouting reinforcement for broken rock mass.

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